Experiment in Terror is a 1962 suspense-thriller released by Columbia Pictures. It was directed by Blake Edwards and written by Mildred Gordon and Gordon Gordon based on their 1961 novel Operation Terror. The film stars Glenn Ford, Lee Remick, Stefanie Powers and Ross Martin.
A psychotic killer, Garland "Red" Lynch, uses a campaign of terror to force San Francisco bank teller Kelly Sherwood to steal $100,000 from the bank for him. Despite his threat to kill her or her teenaged sister Toby if she goes to the police, Sherwood contacts the San Francisco office of the FBI, where agent John Ripley takes charge of the case.
Ripley interviews a woman who implies that she's involved in some way in a serious crime, but before she can give Ripley the details, Lynch murders her. Sherwood continues to be terrorized with phone calls, an asthmatic condition making the unseen Lynch's voice all the more sinister.
The FBI identifies the criminal, noting that Red Lynch has a record of convictions for statutory rape, forgery, criminal assault, armed robbery and murder. They track down his girlfriend, Lisa Soong, whose 6-year-old son has just had a hip replaced. Lynch is paying all the hospital bills.